mirror of
https://github.com/matrix-construct/construct
synced 2024-11-18 07:50:57 +01:00
38 lines
1.5 KiB
C++
38 lines
1.5 KiB
C++
// Matrix Construct
|
|
//
|
|
// Copyright (C) Matrix Construct Developers, Authors & Contributors
|
|
// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
|
|
//
|
|
// Permission to use, copy, modify, and/or distribute this software for any
|
|
// purpose with or without fee is hereby granted, provided that the above
|
|
// copyright notice and this permission notice is present in all copies. The
|
|
// full license for this software is available in the LICENSE file.
|
|
|
|
#pragma once
|
|
#define HAVE_IRCD_CTX_EXCEPTION_HANDLER_H
|
|
|
|
namespace ircd::ctx::this_ctx
|
|
{
|
|
struct exception_handler;
|
|
}
|
|
|
|
/// An instance of exception_handler must be present to allow a context
|
|
/// switch inside a catch block. This is due to ABI limitations that stack
|
|
/// exceptions with thread-local assumptions and don't expect catch blocks
|
|
/// on the same thread to interleave when we switch the stack.
|
|
///
|
|
/// We first increment the refcount for the caught exception so it remains
|
|
/// intuitively accessible for the rest of the catch block. Then the presence
|
|
/// of this object makes the ABI believe the catch block has ended.
|
|
///
|
|
/// The exception cannot then be rethrown. DO NOT RETHROW THE EXCEPTION.
|
|
///
|
|
struct ircd::ctx::this_ctx::exception_handler
|
|
:std::exception_ptr
|
|
{
|
|
exception_handler() noexcept;
|
|
exception_handler(exception_handler &&) = delete;
|
|
exception_handler(const exception_handler &) = delete;
|
|
exception_handler &operator=(exception_handler &&) = delete;
|
|
exception_handler &operator=(const exception_handler &) = delete;
|
|
};
|